Method and apparatus for concentrating pulp water



y 1932- Y o. ANDR ESEN 1,867,436

METHOD, AND APPARATUS FOR CQNCENTRATING PULPWATER Filed Jan. 22. 1929 2 Sheets-Sheet 1 Q Maw y 1932- o. ANDRESEN 1,867,436

METHOD AND APPARATUS FOR CONCENTRATING PULP WATER Filed- Jan. 22, 1929 2 Sheets-Sheet 2 Patented July 12, 1932 UNETED STATES PATENT caries OTTO ANDRESEN, OF VINDEREN, NEAR OSLO, NORWAY METHOD AND APPARATUS FOR GONGENTRATING PULP WATER Application filed January 22, 1929, Serial No. 334,266, and. iuNorway June 30, 1928.

In several industries and particularly in the paper manufacture the problem exists to remove from pulp water a proportion of its water content in order to render the mass more suitable for further treatment. This process, viz: the concentration of the pulp water, is usually carried out in special apparatus straining ofi a proportion of the water in order to leave the pulp at the desired degree of concentration. Ordinarily rotating strainers or screws are used, on the exterior cylindrical sieve clot-h of which a part of the fibres is deposited, whereas the more or less clean water passes through the sieve surface into the strainer drum in order to be conducted away. The deposited layer is removed from the drum in some suitable manner.

In apparatus of this kind it is diflicult, to

prevent some fibres from following with the removed from the compartment together with the simultaneously introduced water or pulp water.

Preferably not the whole of the deposited layer is scraped ofi, but a quite thin layer is left which passes to the next section in order to produce therein a commencing filtering layer preventing the fine fibres in the pulp 1grater from passing through the sievemem- The compartment receiving the concentrated pulp water is preferably maintained completely submerged in the pulp water of the container, so that the concentrated pulp water is removed from the compartments under hydrostatic pressure.

The method forming the subject matter of the present invention is preferably carried out in an apparatus, wherein above a travelling sieve member which is completely or partly 'immerged in the dilute fibre pulp a 1 series of compartments'are distributed suitably apart along the submergedportion of the sieve member, said compartments at the side, where the sieve member travels in, being located at a suitable distance from the sieve member so astoiallow the layer deposited upon the member to travel intothe compartment, whereas each compartment at the opposite side, where the sieve member travels out, forms or is provided with a" scraper which may be adjusted to the sieve member and may operate to loosen therefrom the depositedfibres save in case the quite thin layer to'be left. Y

A simple construction isobtained by making the compartments in the. form of pipes which are provided with a longitudinal open; ing along the portion facing the exterior side of the sieve member, said pipes beingpro vided at one or both ends with outlets for the concentrated pulp mass; The pipes may be arranged adjustably about their axes, so that the distance of the two edges of-the longitudinal aperture from the sieve member may be adjusted by rotating the pipes. p

The simplest construction of the apparatus is obtained, when the compartments are distributed on the exterior periphery of an ordinary strainer drum which together with the compartments is completely submerged in the pulp water, so that water drained oif'is removed in ordinary manner from the drum inside, whereas concentrated pulp water is conducted out separately through the cute rior compartments a If desired the interior of the strainer drum may be subjected to suction, whereby the draining capacity of the drum is increased. The invention is illustrated in the accompanying drawings, wherein Figure l'shows diagrammatically in longitudinal'section a plane sieve member with associated compartments. 'Figure 2 shows a portionof a cylindrical sieve member with pipecompartments in cross section. Figure 3 is an essentially diagrammatic cross section and Figure 4; a longitudinal section of a concentrating strainer drum in a practical construction. Figure 5 is a longitudinal section of 7 another construction.

The principle of the invention will be understood from Figure 1. An endless sieve cloth 1, only a part of which is shown in the drawings, travels slowly in the direction of the arrow and forms a straight portion between the rollers 2 and 3. Above this portion a number of compartments 4 is arranged suitably apart and preferably in the form of pipes with longitudinal slots 5 (see Figure 2), supporting rollers 6 for the sieve member 1 being arranged under each pipe. Above the sieve cloth 1 and opposite the rollers 2, 3 larger rollers 7, 8 respectively are arranged serving to limit both ends of a space 9 which is closed in suitable 'manner (not shown) along both sides, so that the space 9 forms a suitably deep vessel or container having as a bottom the travelling sieve cloth 1. The vessel 9 is supplied with the dilute pulp mass.

By rotation the pipes 4 may be so adjusted that the longitudinal edge of the aperture 5, where the sieve cloth travels into the pipe, is maintained at asomewhat larger distance from the sieve cloth 1 than the opposite longitudinal edge which is maintained in contact with or at a quite small distance from .the cloth. 'The thickness of the pulp layer deposited on the upper side of the cloth l will therefore increase during its travel from the outlet of one compartment 4 towards the lowermost edge of the slot 5 in the next compartment. The layer isscrapedoff by this edge and is distributed in the water which is inside the pipev4 and will form therein a' concentrated pulp water which is passed out to the sides through each of the pipes, However, if the lowermost edge of each aperture or slot 5 is not quite in contact with the sieve cloth 1, the layer isnot scraped ofi completely. A quite thin film is left which will operate as a commencing filter after the sieve cloth has passed out from each pipe 4. This filter prevents even the finest particles the flour particles) from passing through the member 1, so that ony clean water is strained ofl. and is passing down through the sieve cloth.

The concentrated pulp water in' the compartments 4 cannot, on account of the hydro static pressure,escapeback into the vessel 9' again, but it must follow out to the outlet of the pipesand will consequently be positively separated from the dilutepulp water, and-in this manner a continuous operation is obtained without diificulty.

According to Figure 2 the compartments 4 are distributed exteriorly around a cylindrical strainer drum 1. The construction of this drum may be as indicated in Figures 3 and 4. The sieve cloth 1 is stretched between the end walls 10, 11, the hubs 12, 13

of whichare keyed to a rotating shaft 14 supported by stationary bearings and placed in a slow rotation.

parting from the principle of operation describe V v According to Figure 5 the cylindrical sieve cloth 1 is attached to three spoke crosses 18, 19., 20 each of which is keyed to the shaft 14. This shaft is supported by the stationary end walls21, 22 of the drum, one of which'is provided with a stationary outlet 23 for the water drained oil. 24 is the driving wheel (gear wheel) of the shaft. By this construction the hollow pivot in the-drum endwall 11 of Figure 4is avoided.

i'claim: r 1. Method of concentrating pulp water,

particularly fibre pulp for paper making and the like, by strainingv ofi water from dilute fibre pulp, characterized by this that the dilute fibre pulp is introduced into a container having, a travelling sieve 5 cloth, water "is strained ofi upon sections above the cloth, the

mass deposited as a layer upon the cloth'during its travel under each section isscraped off completely and isQconducted into a compartmo ment located at the end of each section and is passed out from the compartment together with water or pulp water received simultaneously in the said compartment.

2. Method of concentrating pulp water, particularly fibre pulp for paper making and the like, by straining off water from dilute fibre pulp, characterized by this that the dilute fibre pulpis introduced into a container having a, travelling sieve clot-h, water is strained ofi' upon sections above the cloth, the mass deposited-as a layer upon the cloth during its travel under each section is scraped off partly, the portion scraped ofl being conducted into a compartment located at the end of each section and is passed out from the compartment together with water or pulp water received simultaneously in the said compartment, whereas the portion of the layer letton the sieve cloth is passed to a 12i next section so as to constitute therein a commencing fibre layer preventing the fine fibres contained in the'pulp water from passing through the cloth.

3. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container, the walls of which are constituted partly by a travelling sieve cloth, means for I supplying dilutelpulp water to said container, 1

means defining acompartment arranged in the container near that end of the wall constituted by said cloth and open to the con tainer and provided with separate outlet, and a scraper formed on said compartment means, adapted to scrape off inside thecompartment the pulp layer deposited uponthe cloth.

:4. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container having walls constituted partly by a travelling sieve cloth, means for supplying dilute pulp water to said container, a number of compartments distributed apart in the container in proximity to the cloth and open to the container, a scraper formed on each compartment and adapted to scrape off from the cloth a suitable quantity of the pulp ClGPOo ited on the cloth and to deliver this pulp quantity in the associated compartment so as to produce therein concentrated pulp water, and outlet means on each compartment for separately removing said concentrated pulp water therefrom.

5. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container having walls constituted partly by a travelling sieve cloth, means for supplying dilute pulp water to said container, a compartment totally submerged in the container in proximity to the cloth and open to the container, a scraper formed on said compart: ment adapted to scrape off from the cloth a suitable quantity of the pulp deposited on the cloth and to deliver this pulp quantity in the said compartment so as to produce therein concentrated. pulp water, and outlet means on each compartment for separately removing said concentrated pulp water therefrom.

6. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container having walls constituted partly by travelling sieve cloth, means for supplying dilute pulp water to said container, a compartment submerged in the container in proximity to the cloth and open to the container and cloth at the side facing towards the incoming cloth portion, a scraper formed on said compartment, at its opposite side, where the clothtravels out, said scraper being adapted to scrape off from the cloth a suitable quantity of the pulp deposited on the cloth and to deliver this pulp quantity in the said compartment, so as toproduce therein concentrated pulp water, and outlet means on said compartment for separately removing said concentrated pulp water from the com partment.

7 In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container having walls constituted partly by a travelling sieve cloth, means for supplying dilute pulp water to said container, a stationary pipe submerged in the container and having a longitudinal aperture facing towards the cloth near the portion thereof travelling out from the container, the edge of the aperture at which the cloth arrives being arranged at some small distance from the sieve cloth, Whereas the opposite edge is adapted to operate as a scraper to scrape off from the cloth a suitable quantity of the pulp deposited on the cloth and todeliver this pulp quantity in the pipe so as to produce therein concentrated pulp water, said pipe having an outlet for separately removing said concentrated pulp water therefrom.

, 8. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container having walls constituted partly by a travelling sieve cloth, means for supplying dilute pulp water to said container, a number of stationary pipes submerged in the con tainer and distributed mutually apart in proximity to the cloth and having each a longitudinal aperture facing towards the cloth, the edge of the aperture at which the cloth arrives being arranged at some small distance from the sieve cloth, whereas the opposite edge is adapted to operate as a scraper to scrape off from the cloth a'suitable quantity of the pulp deposited on the cloth and to deliver this pulp quantity in the associated pipe so as to produce therein concentrated pulp water, said pipes having an outlet for separately removing said concentrated'pulp water therefrom; I

9. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination of a container having Walls constituted partly by a travelling sieve cloth, meansfor supplying dilute pulp water to said container, a stationary pipe submerged in the container and having a longitudinal aperture facing towards the cloth near the portion thereof travelling out from the container, the edge of the aperture at which the cloth arrives being arranged at some small'distance from the sieve cloth, whereas the opposite edge is adapted to operate as a scraper to scrape off from the cloth a suitable quantity of the pulp deposited on'the cloth and. to deliver this pulp quantity in the pipe so as to produce therein concentrated pulp water, said pipe having an outlet for separately removing said concentrated pulp water therefrom, and means for adjusting the pipe around its longitudinal axis so as to enable the quantity of deposited layer scraped off to be adjusted between zero and complete.

10. In an apparatus for concentrating pulp Water, particularly fibre pulp for paper makdilute pulp water-to said container, a number of stationary pipes submerged in the container and distributed mutually apart in proximity to the cloth and having each a longitudinal aperture facing towards the cloth, the edge of the aperture at which the cloth arrives being arranged at somesmall distance from the sieve cloth, whereas the opposite edge isadapted to operate as a scraper to scrape oii from the cloth a suitable quantity of the pulp deposited on the cloth and to delivervthis pulp quantity in the associated pipe so as to produce therein concentrated pulp water, said pipe having an outlet for separately. removing said concentrated pulp water therefrom, and means for adjusting each pipe around its longitudinal axis so as to. enable the quantity of deposited layer scraped oif in each pipe to be adjusted between zero. and full.

11. In an apparatus for-concentrating pulp Water, particularly fibre pulp for paper making and the like, the combination with a container of a strainer drum submerged therein; means for rotating thedrum; means for removing water fromv the interior of the drum; and means defining stationary compartments distributed outsidethe drum in proximity'to its sieve cloth and open towards the same, a scraper provided for each compartment and adapted to scrape off from the cloth a suitable quantity of the pulp depos ited on the cloth and to deliver this pulp quantity in the associated compartment. so

vas to produce therein concentrated pulp f water, and outlet means on said compartments for separately removing said concen trated pulp water from each compartment. I 12. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination with a contamer of a strainer drum submerged therein, means for rotatlng the drum, means for removing water from the interior of the drum,

- means on said compartment for means for establishing a reduced pressure inside the drum, stationary compartments distributed outside the drum in proximity to its sieve cloth'and open towards the same, a scraper formed on each compartment and adapted to scrape oif from the cloth a suitable quantity of the pulp deposited on the I cloth and to deliver this pulp quantity in the associated compartment so as to produce therein concentrated pulp water, and outlet separately removing said concentrated pulp water from each compartment. k

13. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination with a container ofa strainer drum submerged therein, means for rotating the drum, means for removing water from the inte means for establishing a reduced pressure inside the drum, stationary submerged com rior of the drum, 7

partments distributed outside the drum in proximity to its sieve cloth and open to the container and to the cloth at theside facing towards the incoming cloth portion, a scraper formed on each compartment at its opposite side, where the cloth travels out, said scraper being adapted to scrape oif from the cloth a suitable quantity'of thepulp deposited on the moving water from the interior of the drum,

a number of stationary pipes submerged in the container and distributed mutually apart in proximity to the cloth and having each a longitudinal aperture facing towards the cloth, the edge of the aperture at which the cloth arrives being arranged at some small distance from the sieve cloth, whereas the opposite edge isada-pted to operate as a scraper to scrape ofi from the cloth a suitable quantity of the pulp deposited'on the cloth and to deliver this pulp quantity in the pipe so as to produce therein concentrated pulp water, said pipes each having an outlet for separately removing said concentrated pulp Water r'om the pipes. V p 15. In an apparatus for concentrating pulp water, particularly fibre pulp for paper making and the like, the combination with a container of a strainer drum'submerged therein, means-for rotating the drum, means for removing water from the interior of the drum, a number of stationary pipes submerged in 7 the container and-distributed mutually apart in proximityto the cloth and having each'a longitudinal aperture facing towards the cloth, the edge of the aperture at which the cloth arrives being arranged at some small from the pipe, and means for adjusting each 7 pipe around its longitudinal axis so as to enable the quantityo'f deposited layer scraped off in each pipe to be adjusted between zero and full.

- In testimony whereof Ihavevsigned my name unto this specification.

- orro ANDRESEN. 

